Flotation of pyrites from a pyrite ore pulp



Patented-Apr. 28, 1953 7 '1.1g; FLOTATIQN OF PYRITES F RoM A'PYRIrE I I f ORE PULP, 32

.Arvid Emil Anderson, Cornwall, Pa., assignor to Bethlehem Steel Company, a corporation of Pennsylvania No Drawing. Application June 17, 1949, Serial No. 99,883

2 Claims.

My invention relates in general to the concentration of mineral substances by froth flotation, .and in particular to a flotation reagent for the recovery of iron pyrites (FeSz) and related sulphide ores.

In the froth flotation of iron pyrites, the reagents added to the aqueous ore pulp consist usually of copper sulphate (01.1304) a collector or promoter, and a frother, which are separately fed .to the pulp in a fiotationmachine in the order given. The copper sulphate is added in the form of a saturated water solution in amounts equivalent to 1.03 pounds per ton of dry feed, and simply cleanses the surface of the pyrite particles in aid of subsequent reactions. The collector brings together selectively the mineral particles to be recovered, While the frother creates the floating froth or foam which suspends the collected particles. Most reagents require the pulp to be heated for an effective separation. In

some instances, activators or depressors are also added, ahead of the collector, but in nearly all cases the frother is added last.

I have discovered that the single addition of my improved pine oil-resinate-xanthate-water emulsion will simultaneously perform the functions of collector and frother, and will produce a more selective and powerful reaction with the sulphide minerals than previous reagents, with its efiectiveness retained at lower temperatures.

The principal object of this invention, therefore, is an increased recovery of pyrites with decreased consumption and costs for reagents.

In accordance with my invention, a xanthateresinate-pine oil-water emulsion of good stability is prepared, and this emulsion is added after the copper sulphate step to the pulp in the flotation operation, thus eliminatingthe additional twostep process of feeding the collector and frother separately.

To make 178.9 liters, or 47.08 gallons of my reagentjthis being a convenient quantity for storage in a standard 50-gallon drum, 108 grams (3.81 oz.) of Dresinate XXX (trade name for sodium resinate) is dissolved in 10.8 liters (2.86 gals.) of G. N. S. No. 5 pine oil, to form a 1% (by weight) solution of Dresinate in pine oil. The resultant solution is added to 5.4 liters (1.43 gals.) of water and homogenized, under about 700 to 800 p. s. i. pressure, to form a Dresinatepine oil-water emulsion resembling a thin marshmallow syrup. This first emulsion is then-added to 108 liters (28.6 gals.) of a (by weight) solution of sodium ethyl xanthate in water, togeth- ,er withan additional, liters (1.4.3 gals.) of water, and the mixture is again fed through the homogenizer, with pressure set as before.

In other words, the proportions of the liquid constituents of the emulsion are substantially as follows: pine oil, parts; sodium ethyl xanthate solution, 500 parts; and water, 300 parts.

The pine oil functions chiefly as a frothing agent, but as a practical matter it is almost impossible to form a stable pine oil-water emulsion Without the help of an emulsifying agent. The

addition of the small amount of Dresinate XXX, however, produces a very stable emulsion and also improves the recoveries of pyrite. This emulsion, as mentioned above, is then further emulsified with the xanthate to form a xanthatepine oil emulsion.

The major collecting effect is produced by the xanthate, which is the reaction product of an alkali metal hydroxide, carbon disulphide, and an alcohol. As stated, I prefer to use a 25% solution (in water) of sodium ethyl xanthate, which is the reaction product of sodium hydroxide, carbon disulphide, and ethyl alcohol, as the xanthate component, but sodium iso-propyl xanthate solutions, while somewhat less effective for the recovery of pyrite, may also be used with success. The reaction of the xanthate with the collected pyrite is to form an insoluble xanthate which is air avid and hence is strongly attracted to the bubbles of the froth.

This emulsion does not show the effects of de composition or loss of strength over ordinary periods of time, as is normally the case with xanthates, and mixes very evenly and quickly with the feed. Actual plant tests indicate that an increase in pyrite recovery of about 3%, with about 10% less reagent, is readily attained with its use in conventional types of-flotation machines.

Although I have thus described my invention,

in considerable detail, I do not wish to be limited to the exact and specific details shown and described, but may use such substitutions or equivalents thereof as are embraced within the scope of the invention or pointed out in the appended claims.

I claim:

1. A method of recovering pyrites from a pyrite ore pulp which comprises adding to the pulp an emulsion of a xanthate, pine oil, and sodium resinate, and subjecting the pulp to a flotation operation.

2. A method of recovering pyrites from pyrite ore pulps which comprises adding to the pulps an emulsion of sodium ethyl xanthate, pine oil. and

sodium resinate, and subjecting the pulps to a Number Name Date froth flotation operation. 2,259,420 Hills Oct. 14, 1941 ARVID EMIL ANDERSON. 2,286,374 Ray June 16, 1942 OTHER REFERENCES Weinig eteal. The TrencLof. Flotation, Quarterly of the Colorado. School of Mines, v01.

References Cited in the file of this patent 5 UNITED. STATES N m er Name Dht'e XXX-II, No. 4, 1937, page 59.

145473732 Broadbrldge et July 28, 1925- Bureau of Mines Bulletin 449, Development 1,554,216 Keller f 1925 v t and Use' of Certain Flotation Reagents, 1944, 1,992,949 Hodges .mw 5 p pages;- 5; third? paragraph; and pages 7 -79- 2.116,'727 Lenher et 21. May 10, 1933; 

1. A METHOD OF RECOVERING PYRITES FROM A PYRITE ORE PULP WHICH COMPRISES ADDING TO THE PULP AN EMULSION OF A XANTHATE, PINE OIL, AND SODIUM RESINATE, AND SUBJECTING THE PULP TO A FLOTATION OPERATION. 